Seal for well tubing



May 12, 1953 E. N. JONES 2,638,167

SEAL FOR WELL TUBING Filed June 28, 1948 Eol/l/a/rcz/ N. dones W INVENTOR.

B w/fwuy' l] ATTORNEYS Patented May 12, 1953 STATES QFFICE SEAL FOR WELL TUBING.

EdwardN.. Jones, Retina. Tex..

Application .Iune- 28, 194:8y SeriaI'No. 35,571.1.

61 Claims. 1.

This inventionY relates to improvements inseals for well tubing., and' more particularly to devices forternporarily sealing a string of casing, tubing or other pipe, in an oil' We11,` aswhile the string isbeing lowered` into a borehole containing fluids, and; for temporarily restricting the upward4 iiow Qffuid through the string after the seal is broken, as when completing the well.

important object' or' this invention is the provision of meansv for speedilycompleting a well while maintaining controls over the fluids under pressure therein Anotherobj ect'of' this invention is the mounting in juxtaposition in a, well' tubingof" a rupturable sealing member and an credible choke or restrictor member', whereby flow ofyfluids under pressure through the tubingv can be preventedas long as desired and then` restricted until the pressures above and below the choke member have been substantially equalized, permitting use of the usual ground flow control equipment to control the further iiow of well fluids.

A further object off this inventionl is the coaction of temporary sealing means for well tubing` and means for breaking the seal whenever desired', substantially all of' which willjbe removed from thewell by the flow of Well iuids.Y through I is a longitudinal' section of'one form off my improved seal'.

Fig. 2. is a fragmentary` section of another form thereof.

Fig. 3j isa longitudinal section of a penetration tool for rupturing, the. seal, and;

Fig; i isa longitudinalsection of still another form of" my improved seal',

In the, form ofl the device shown in Fig. 1, there is provided al sleeve or shell l with terminalmala elements` la and lb exteriorly threaded for` engagement, with, interiorly threaded female members. 2a and. 3.a of tubing sections Zand 3, respectively.

The upper element. lo is, provided in. its outer face with an annular, inner peripheral seaist 4S providing an. annular,4 outer peripheral flange `5. FittingT in.L the seat Lis` a` plate 6. Qi. Suitable ma.-

.teriar., such as sheet metal., and. havingl suchV diameter and thickness as to conform nicely with the seat Q; so that when shell; lI is'y set upA in section 2, the flange 5 and plateV 6 are ctamped againstV the endof' section 2A by the, screw action or the :zo-acting threaded) parts` to effect asealed joint between shell I and tubing section 2'. The sleeve- I- is interior-ly enlarged to provide a: recentacl'e I` and a shoulder 8' fer-a choke plug 9- ofsu-itable; easily credible material',` such as mag"v nesium, and which is; immobilized in theV recep tacle l, betweenthe shoulder 8 andi section 3, when'4 the section is set up on the'shell l., Choke plug 8" a longitudinali, axial4 bore; i0 or comparativel-y small' initial diameter; but` winchr is rapidly enlarged as the now-orfiuidstherethrough proceeds, as hereinafter described.

In the form of the device shown in Fig; 2; the sleeve MV has a termi-nal* rnal'e-elementA Hw with `a plane outer end No engaging a'plate l2, ot'- suitablfe, easily erodible` materia-l; such as mage nesium, seated in the section' r3; It will be noted that the parts are so dimensionedi that when the shell it isset up in` the sect-ion It and bears against the plate F2* there remains a slight gap G, inV which is fitted=` a suitable Washer W, between the outer4 end of` the; section I3 and* the unthreadedj portion of the; shell H, so tl'raty the plate l'il'lis clamped between theeshel'l; H and'` the section I3 by the screwy action of the co-acting threadedi parts to effect a. sealed joint therel between.

The female member Pta in which isA received* the male member Har a setrscrew' Nr to immobilize" thel assembled parts inv such `sea-led*relation. The pla-te |"2Y has" annular grooves I-2 or the like cut* initsi upperA and nether surfaces to provide aY weakened-portion F217 anda guide for retaining acid or the` like in engagement with suchweakened portion when the seal is to be broken.

The penetration too-l T; shown in Eig. 3; hasV a shelll t5 or suitable,` easily erodible material; suclr as magnesium. a capl f6 of the-same material anda suitable euttinghead Fl; The shell l-5A is preferably loadedwith a charge t8* or suitable-- liquid of high; specic gravity, such as' mercury;,to provide suicient weight to insure proper functioning of the tool T'.

In the form of, the device shown in Fig. 4.', the shell 20' has a shoulder 2l against whichisseated a choke, )blugA 22. snugly tted in the shell 2li andl having a reduced portion 22a provided, with` packing means to effect a, sealed joint. between the` shell. .fl,A andtneplug 22. Any suitablevv paolo-` ins. means. may, beA employed to provide a.Y seal between the choke plug and shell 20 such Orings, chevron packing or the like. In the embodiment of the drawings, the packing means comprises a pair of packing rings 23 and a pair of collars 24 and 25 about the reduced portion 22a. The rings 23 are of any suitable material and frusto-conical in cross-section to provide convergent faces 23a, 23h. Each ring 23 has an interior iiange 23o fitted closely about the portion 22a to provide annular spaces about the portion 22a to receive therein the sleeve portions 22u and 25a of the collars 24 and 25, respectively, their ends bearing on .the fianges 22e, respectively. The face 23a of the ring 23 disposed at the inner end of the portion 22a is juxtaposed with an inclined annular` flange 22h on the plug 22, and the face 23o of this ring is juxtaposed with an inclined annular flange 2th on the collar 2t. The collar 24 has a plurality of grooves 24e in the outer surface of the sleeve portion 24a connected respectively with a plurality of bores 24d, debcuching into the spacebetween the reduced portion 22a and the shell 2li.

The face 23a of the ring 23 disposed toward the outer end of the portion 22a, is juxtaposed with an inclined annular flange 245e on the collar 24, and the face 22h of this ring is juxtaposed with an inclined face iilb of the collar 2li. The collar 25 has the grooves 25o and bores 25d identical with those above-mentioned.

A follower 2t is threaded on the lower end of the portion 22a and serves to force the interposed washer v2l against collars 25 and 2t to apply expanding pressure to the rings 23 to effect a seal between the shell 2b and plug 22.

The plug 22 has a longitudinal axial bore 28 debouching at the lower end of the portion 22a. and having its upper end spaced from the upper end of the plug 22 which has a central depression 22o whereby a closed portion 23a. is formed between the upper end of the bore 22 and the depression 22 The container 29, a fragment of which is shown in the upper part of Fig. 4, is designed for a suitable acid (not shown) for attacking the seal member (l2 of Eig. 2 and thin part of 22 of Fig. 4). The container is provided in its bottom with a check valve Sil having a head 3l projecting outwardly of the container 29.

will now explain the use and operation of the several forms of my improved device which have been hereinbefore fully described.

The device shown in Fig. 1 is assembled and functions as follows. The tubing section 2 is 'threaded into or near to the lower end of a string of tubing. The plate S is placed in the seat 4 of the shell and the shell I is set up in the section 2 to clamp the plate ii between the shell I and section 2 in a sealed joint to effectively close the channel in the string of tubing. rlhe choke plug Si is then placed in the receptacle l of the shell i and the section 3 is set up on the shell I to clamp the plug between the shoulder 8 of shell I and section 3. rlhe device, thus assembled as shown in Fig. l, is conditioned to function. The section 3 may be provided with a suitable screen (not shown) 'to protect the device from debris which might otherwise collect in the section 3 and block off the bore it in plug 9.

The string of tubing is sufliciently lowered into the well bore to dispose the shell I at the proper point for opening the channel through the string of tubing.

The flow connections are made at the ground surface to control the flow of the well fluids. The penetration tool T (Fig. 3). dropped free or 10W- ered by a wire through the string of tubing, iinpinges upon the plate 6 with such force that its cutting head I1 punctures the plate 6 to break the seal of the channel through the string of tubing. The well fluids will enter the tubing due to the pressure differential across plate 6. As the fluids are forced by this pressure through the bore I0, the plug 9 becomes rapidly eroded by their passage therethrough due to the mechanical action of the abrasive matter in the fluids and also due to the corrosive action due to acidic materials in the fluids. It is obvious that the choke plug 9 thus controls the rate of ow of the well fluids until the pressures above and below the device become equalized. This condition becoming established, the ground flow control equipment functions to control the rate of flow of the well fluids.

vIt. is obvious that the liow of the fluids will rapidly disintegrate the casing I5 and cap It of tool T, releasing the fluid I3 to mingle with the well fluids, thereby eliminating the tool T as an obstruction in the tubing after it has functioned.

The device shown in Fig. 2 is assembled as the device of Fig. l above described and the set-screw Ill is set up to lock the sleeve I I lin the section I3. The plate I2 is punctured by pouring a suitable acid down the string of tubing or supplying it by the receptacle 29 (Fig. 4) lowered to strike plate I2, the head 3i striking the plate I2 to release valve 30 to allow the acid to flow out of the container 2S. The acid, supplied in either of these ways, accumulating in the groove I2a, on the upper surface of the plate I2, attacks the reduced thickness of the material of the plate I2 quickly severing the weakened portion I2b to rupture plate I2. The plug 9 of this form of the device functions as above described and the annular portion of plate I2 is also eroded by the passage therethrough of the Well fluids, to eliminate any obstruction in the tubing. v

The device shown in Fig. 4 is assembled by mounting rings 23 and collars 2.4 and 25 on the portion 22a of the plug 22 and holding them thereon by the washer 2l and follower 2S which is as yet not setl up to expand rings 23. rlhe assembled parts are then mounted in sleeve 28 the plug 22 being seated on the shoulder 2l. The follower 2t is then set up urging collars 24 and 25 to expand rings 23 to effect a scaled joint between sleeve 2o and plug 22. The sleeve 2o is then introduced in the string of tubing at the desired point thereof.

It will be noted (Fig. 4) that the bores 24d, 25d and the grooves 26e, 25e of the collars 24 and 25 afford passages through which pass the well fluids under pressure flow to exert expanding force upon the packing rings 23 to augment their scaling action.

When the receptacle 29. is dropped or lowered through the tubing to impinge on the plug 22 the `acid in the container liows therefrom into the depression 22o on the top face of the plug 22. If convenient the acid may be poured down the tubing without use of the container 29. The acid, supplied in either of these ways, accumulating in the depression 22e, attacks the thin web of the plug 22 between the receptacle 22e and the upper end of the bore 22, and rapidly eats through this web to open the bore 28 to admit the well uids therethrough to the string of tubing. The choke plug 22 then functions as plug 9 as above described.

The Fig. 4 device is preferred for it may be forced downwardly out of shell 20 and the tubing connected to the lower end thereof by applying pressure to the upper face of member 22 to break the seal and remove the plug if this should become desirable, as for instance: in the event of a blow out, to permit circulation of drilling liuids to establish control; or to permit completion of the well if bore 28 should become plugged with debris when the tubing is lowered within a Well bore. Also with this structure the thickness of the material of the choke plug 22 to be destroyed by acid to make the tool function may be less than in the Fig. 2 modication providing faster action.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having described my invention what I claim is:

1. In a seal for Well tubing, the combination of a sleeve having means for mounting said sleeve to form a part of the tubing, a choke plug in said sleeve and having a reduced portion with an axial bore extending within the reduced portion, a closure closing the upper end of the bore and constructed of acid-dssolvable material, a central depression in the upper end of said closure adapted to confine acid inserted above the plug to direct the dissolving of the closure to that portion thereof above the axial bore, a packing ring, expansible radially of said portion, an expanding collar, axially movable on said portion, and means on said portion for moving said collar to expand said ring to effect a seal between said sleeve and said plug.

2. In a seal for well tubing, the combination of a sleeve having means for mounting said sleeve to form a part of the tubing, a choke plug in said sleeve and having a reduced portion with an axial bore extending within the reduced portion, a closure closing the upper end of the bore and constructed of acid-dissolvable material, a central depression in the upper end of said closure adapted to confine acid inserted above the plug to direct the dissolving of the closure to that portion thereof above the axial bore, a packing ring, expansible radially of said portion, an expanding collar, axially movable on said portion, and means on said portion for moving said collar to expand said ring to effect a seal between said sleeve and said plug, said collar being provided with conduits for fluid under pressure, said conduits being positioned to supply said fluid to said ring to augmenty its sealing action.

3. In a seal for Well tubing, the combination of a sleeve having means for mounting said sleeve to form a part of the tubing, stop means interiorly of the sleeve, a choke plug within the sleeve on one side of the stop, seal means providing a seal between the plug and sleeve and a passage in the plug extending axially substantially but not quite the length of the plug, a central depression in the upper surface of the plug, a thin web of material between said depression and said passage, whereby acid may accumulate in said depression for dissolving said web to open saidpassage at its upper end.

4. In a seal for well tubing, the combination of a sleeve having means for mounting said sleeve to form a part of the tubing, a choke plug mounted within the sleeve and comprising a cylindrical body having an axial bore extending from its lower end to a point spaced from the top of the body whereby the upper end of the bore is closed by a relatively thin section of the material of which the body is constructed, the body being constructed of an acid-dissolvable and erodible material and having a central depression in its upper end over said thin section of material, whereby the upper end of the bore may be opened by dissolving the material closing said bore with acid after which the body will be eroded by iow therethrough, and means carried by the exterior of the plug for sealing between the plug and the sleeve within which said plug is mounted.

5. The combination set forth in claim 4, wherein the sealing means comprises annular packing rings with means for admitting the pressure from below the plug within said rings to assure sealing contact of the rings with the inner wall of the sleeve.

6. In a seal for well tubing, the combination of a sleeve having means for mounting said sleeve to form a part of the tubing, a choke plug in said sleeve, means for retaining said plug in said sleeve, said plug comprising a cylindrical body having an axial bore extending from its lower end to a point spaced from the top of the body. a central depression in the upper end of said body, a thin web of material between said depression and said axial bore, whereby acid admitted into said tubing above said plug is conned in said depression to dissolve said thin web for opening the upper end of said axial bore so that well fluids may `pass therethrough from below said plug to the tubing thereabove.

EDWARD N. JONES.

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